From mboxrd@z Thu Jan 1 00:00:00 1970 From: Simon Horman Subject: Re: [RFC net-next] ipv6: Use destination address determined by IPVS Date: Wed, 16 Oct 2013 11:13:06 +0900 Message-ID: <20131016021304.GA17801@verge.net.au> References: <1381881751-6719-1-git-send-email-horms@verge.net.au> <1381882426.2045.85.camel@edumazet-glaptop.roam.corp.google.com> <20131016002807.GM22321@verge.net.au> <1381883949.2045.97.camel@edumazet-glaptop.roam.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: YOSHIFUJI Hideaki / =?utf-8?B?5ZCJ6Jek6Iux5piO?= , lvs-devel@vger.kernel.org, netdev@vger.kernel.org, Julian Anastasov , Mark Brooks To: Eric Dumazet Return-path: Content-Disposition: inline In-Reply-To: <1381883949.2045.97.camel@edumazet-glaptop.roam.corp.google.com> Sender: lvs-devel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Tue, Oct 15, 2013 at 05:39:09PM -0700, Eric Dumazet wrote: > On Wed, 2013-10-16 at 09:28 +0900, Simon Horman wrote: > > > > I guess things like NFQUEUE could happen ? > > > > Could you expand a little? > > This was to point that between IPVS and ipv6 stack we might have a > delay, and daddr was maybe pointed to a freed memory. > > IP6CB only uses 24 bytes, so I think you would be safe adding 16 bytes. That does seem very promising but while implementing it I hit a problem. struct tcp_skb_cb includes a field of type struct inet6_skb_parm. And expanding struct inet6_skb_parm by 16 bytes means that struct tcp_skb_cb is now larger than 48 bytes and no longer fits in skb->cb. Is it appropriate to grow skb->cb as the comment above struct tcp_skb_cb suggests?